Partition sheet for loose-leaf devices



Patented Mar. 20, 1928.

UTED. 'i

ALFRED M. MARTIN,

0F CHICAGO, ILLINOIS.

PARTITION 'SHEET FOR LOOSE-LEAF DEVICES.

Application filed July 6,

My Patent No. 1,269,479'of June 11, 1918 on loose-leaf binders shows atype of looseleaf binder with which the present 'partition sheet ispeculiarly advantageous. In that patent Figs, 8 and 9 illustrate a formof partition sheet described. therein as an indexed leaf for separatingthe account leaves. y

In the present specification such account leaves will be described ascards. In practice such cards are of various sizes and are usually 'ofpaper stock of ordinary thickness. Their depth from top to bottom) issuch that they may e applied to the binder prongs in overlapped relationwith a narrow p portion of each card exposed, thus forming a series ofsuch cards from top to bottomof 'the binder.- Such overlapping of thecards causes the thickness of the series 4to build up gradually in the,direction in which .the ards or sheets are applied, reaching itsmaximum Where there is a maximum of such cards overlapping -each other,the thickness then diminishing toward theA opposite end of the series.Ordinarily the greatest thickness of the series develops near thecentral portion, measuring. from top to bottom.

A single binder may contain a large num. ber of such series ofoverlapped sheets, say twenty-five or more. With the ordinary atdivision or partition sheets between these respective series the book orbinder device mayl befilled solidly throughout the middle portionthereof whileat the top and bottom portions there is considerable space.This v arises from the fact that at the very top and at the very bottomofthe device there may be only say twenty-five of the cards .between thetwo outer covers, while at the same time there may be in the middle twohundred and fifty or'more of .such cards between the opposed covers.

The object ofthe present improvements,

like that of the device ofl Fig. 8 of my said patent,'is toprovide aidivision or partition sheet for such uses which will occupy spacebetween adjacent series of the overlapped cards, preferably at bothv thetop and bottom ortions of the overlapping series,

where y each series will be maintained more nearly flat when the book isopened and therefore be more free ofthe upwardly bulging effect. of themiddle portion of the series, with certain advantages in practice suchas a more free, movement of the cards on the binder prongs, the cardsbeing relieved of .1926. serial N0. 120,551.

masse from one side ofthe book to the other' more freely and moreeasily. In this connection it may be mentioned that the maintenance ofsuch-a Amore Hat surface atthe top of the series `is of particularadvantage in the act of writing on the upper cards since otherwise thisupper portion of the series would slope downward and away from thewriter. Such a slope may be to quite a great extent; for instancetheremaybe a difference of more than an inch and a half between the thicknessat the middle and at the ends in a binder designed yfor two-inchcapacity. 1

While had in mind these advantages in the division sheet shown in Fig. 8of my -said patent, I have found that such applied thicknesses as aretherein illustrated have various' objections, suchas the Working looseof the applied parts, the catching thereagainst of the overlapped cardsin the device during manipulations, the unnecessary stiffness of -thesheet and its lack .of pliability in certain directions and atparticular places, too .great cost, and increasedweight. The presentimprovements .have for their specic 'objects the overcoming ofthoseobjec-v tions While providing -the described advanta ecus results.

n the drawings Figure 1 is a fragmentar elevation of a binder which maybe consideredv to be of the. kindshown in my said patent and containingseveral series .of overlapped cards and division sheets 1n vtheirlnormal arrangement, the series of cards he.

ing shown in edge view at right angles to the longitudinal direction ofthe series respectively; Fig. 2 is a face view of a-d1v1 sion sheetshownlone type of embossed formations therein thickness of the sheet at upperand lower vportions thereof; Fig. 3 is a fragmentary section, on anenlarged scale, of a porticn of Fig. 2 as on the line 3-.3 thereof; Fig.pis a face'view similar to thatof Fig. 2 vshowing a division sheethaving the' pre-- ferred construction and arrangement of integral-vthickening means,vhere shown as embossed or pressed-up elements intaperel and Acontinuous form; Fig. 5 is lan enlarge or increasing theeffective vlos - sectional view as on the line --5 of Fig. 4;

and Fig. 6 is a fragmentary bottom edge view of the sheet of Fig. 4.v

Referring first tol the preferred'construction Of-Figs. 4, 5 and 6, thepartition sheet 16 is to be considered as being of paper stock of goodquality and of such thicknesses is ordinarily used for division sheetsin looseleaf binders. Ordinaril. what is known -as thirty-pound tothirtyfour-pound stock is used for such purposes. At both top and bottomportions of sheet '10 the material is pressed out of its normally flatshape, preferably by means of heated dies and a .preliminary applicationof steam, with rib-like. projections 11 extending longitudinally up and.down in substantially parallel arranrrement and projecting away fromthegeneral plane of the sheet, forming a` corrugated structure. Fig.6 showshow t e edge of the sheet' has a sinuous formation and how theserib-like projections are formed alternately in posite sides of thesheet.

the ,0P-

These rib-like formations 11 I- respectively decrease in relative heightor vprojection away from the general plane of the sheet to a point 12,wherethey merge into the general plane of the sheet. Withsuch anarrangement and construction the end portion of t e sheet becomesgradually thickened effectively from, some 'place which may be near themiddle of the sheet toward the end.

These lon and narrow and preferably gradually wi enin and thickeningprojections fin Fig. 4 may also 11 are prefera ly close togetherand-extend from one side edge of the sheet tothe other, excepting thatwhere the holes 13' forthe prongsoccur the rib-like formationmay beomitted, and the vri ht-hand edge as shown purposesof applying index'tabs thereto. The desideratum is to havethe .whole `gen eral area ofthe sheet at both the top and the bottom portions thereof well 'coveredby such sheet-thickening formations, and to have the thickening effectsproduced in gradually increasing amounts from nothing to such an amountas is necessary for the dcsi red results.

As to the amount-of effective thickness which should be developed inthe.' sheet, the` .maximum extent thereof, and 'where it should beginare variables depending upon such factors as the thickness of the cardsbelng employed in a particular book or binder,

the-depth of'such cards, and their particular arrangement' with respectto the degree or amount ofthe part of each card exposed beyond theoverlap of the next in the' series.'

With cards of the thickness ordinarily employed the actual amount ofeffective thickness developed in each sheet isA not very reat, say onlyabout lone-sixteenth of an inch at the top and bottom. This matter .oftheeective thickness of .the division e Afree of them for the` ,withinthe scope .lower end portions of the sheet sheets is not highly criticalas the main object is to overcome the great dlsparitybe- -tween themiddle and ends of the book.

Small variations from a truly Hat'sha'pe of the series of cards are notimportant. It will be clear from a foregoing statement that .thepartition or division sheets 10 in Fig. 1

them. Fig.` 1 therefore illustrateshovv this.; .objection is overcome bymaintaining the several series of cards in a fairly fiat shape throughthe use of division, sheets as lherein described. A

The modification of Figs, 2| and 3 shows la pluralityv of circularandrounded projections as 20, 21, 22, 23, 24, 25 and 26 extend. ing on'one side only of the general. plane of the sheet 30 and graduallydecreasing in height fromthe maximum in the edge line .There arenumerous up-and-down lines of such projections 20 to 2 6. inclusive,andsuch projections cover the whole general area of the end portions ofthe sheet. They reduce a sheet .whichgradually becomes e ectivelyofpro'ections denominated 20 to theinnermostlme ofprojcctionsdenominated 26.

thicker both toward the upper and the lower I hese circular projections,likethose of Fig.l 4, may beformed -by dies, preferably to practiceswell understood in thepaperforming art. "Asheety so formed maintains-1tsgeneralshape uite well under conditions of use.;` Whet erinaccordance with Fig. 4 or Fig.' 2, ithas notable properties offlexibility-. The cards ,do not catch upon such projections, and nothinghasfbeen added in weightto the sheet.' The manufacturing operationsaresimple and of low cost.

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with steam to soften the paper, according y l I am aware-of variousother forms and' arrangements .of-- projections which 'may be emplo ed,'and I contemplate as being include herein all constructions..which fallof the appended claims.I

@I-clamzf 1. A partition -sheet for loose-leaf binders of thecharacterdescribed, said sheet being gibstantially rectangularv and4having side having insensata side 'edge' portion thereof for holding-1tin the binder, thealpper and jacent to v andtop .andbottom edgesdefining the vsu antially rectangular shape, .the sheet -over the Wholegeneral surface of such end portions respectively between said hold-ingvmeans and the opposite side edge and providing such end portions with aneffective thickness greater 'than that of the normal thickness of thesheet material from which made, the middle portions in the up and downdirections of the sheetbetween said' end portions and between saidholding means at one side edge portion and the side edge oppositethereto being free of such' projections.

2. A partition sheet for loose-leaf binders of the character described,said sheet having means at a side. edge portion thereof for holding thesheet in the binder, the upper and lower end portions of the sheet beingformed-With integral projections extending over the whole generalsurface of such end portions respectively p andv providing` sucli endportions With an effective thickness the sheet material from which thepartition sheet .is made, said proJections increasing gradually inheight from positions nearer to the medial ,portion of the sheet towardthe upper and the lower ends of the sheet respec tively.

3. Theconibination .of claim 2 hereof lin which said projections arecontinuous and rib-like and extend substantially parallel with the sideedges of the sheet.

ALFRED M. MARTIN.

lgreater than that of the normal thickness of

